A 15-year-old American high school student was beaten and jailed by Israeli police in what his mother called an “attempted murder," as the incident happened a day after his cousin was killed.

The teen, Tariq Abu Khdeir from Tampa, Florida, was on a summer holiday with his parents and sisters in Jerusalem, visiting family in the eastern part of the city. Video clips posted online show three Israeli police officers in riot gear repeatedly beating a young Palestinian, identified as Abu Khdeir by his family, and dragging him away to arrest him.

On Wednesday morning, Tariq’s cousin, 16-year-old Muhammad Abu Khdeir, was murdered in what is widely believed to have been a revenge attack for the recent kidnapping and murder of three Israeli Jewish teens.

Tariq was arrested on Thursday evening. Photos of him in detention show his severely swollen and bruised face, which his mother, Suha Abu Khdeir, said was unrecognizable when she first saw him following the arrest.

“I could not believe it,” she told ABC News. “When I finally looked over at him, it was a feeling that I’ve never felt before in my life.”

There have been daily clashes between Palestinian youths and Israeli police since the murder of Muhammad Abu Khdeir. The Abu Khdeirs said Tariq's arrest happened as he left his uncle's house after playing with his cousins. He was covering his face, they said, because of the tear gas set off at nearby clashes.

The police dispute the account, saying he was part of a group of six masked youths who were armed with three knives, resisted arrest and attacked the officers.

“This is a video edited and biased that does not represent the events,” police spokesman Micky Rosenfeld said in a statement to ABC News. Asked if he’s denying the beating in the video clips took place, Rosenfeld responded: “Obviously incidents took place before or after that the suspects were involved in.”

“How does a 15-year-old American student end up attacking security officers and rioting with hundreds of masked Palestinians??? [sic]” Rosenfeld asked in a text message.

Rosenfeld said he didn’t know whether Abu Khdeir was the teen being beaten in the video or whether he was armed himself. Abu Khdeir’s parents said they recognized him in the clips from the clothes he was wearing, including his baggy pants.

“Palestinians live like this every day. They kind of say 'we’ll deal with it,'” his mother said. “But as Americans, it’s just not human.”

Suha Abu Khdeir was born and raised in Baltimore, where she met her husband Salah. He had emigrated in 1996 from the Jerusalem neighborhood of Shuafat where the beating took place. The couple then moved to Florida, where they had three children and Salah opened a Mediterranean restaurant.

This was their first trip to Jerusalem to visit family in 11 years, a vacation Tariq had long wanted to reconnect with his family and roots.

The visit was rocked by Wednesday’s murder of his cousin Muhammad, abducted before dawn prayers by whom family and neighbors say were right-wing Israeli Jews seeking revenge for the murder of three Israeli teens kidnapped last month in the West Bank. Israel’s government swiftly condemned Muhammad Abu Khdeir’s murder but has not said whether Israelis were behind it.

The autopsy has not yet been released but on Saturday a senior Palestinian official said results show that Abu Khdeir was set on fire and burned alive. He was found in a wooded area west of Jerusalem.

The incidents have given rise to some of the most dangerous tension seen in years. Following the kidnapping of the three Israeli teens, Israel launched a huge crackdown in the West Bank on the Palestinian militant group Hamas, which Israel accuses of being behind the abduction. An uptick in the number of rockets launched into southern Israel from Palestinian militants in the Gaza Strip has followed, and Israel’s military has responded with air strikes.

American officials at the consulate in Jerusalem and embassy in Tel Aviv would not respond to requests for comment since the Abu Khdeir family has yet to sign a privacy waiver. But the parents said they are going with U.S. officials to see Tariq on Saturday afternoon ahead of a court session on Sunday.